Kohlrabi, radish, and beet, especially their purple variety, might look similar enough to be considered members of the same vegetable family. Not so. Kohlrabi and radish belong to the Brassicaceae family, also known as the Cruciferae or mustard family. They include kale, broccoli, cauliflower, cabbage, Brussels sprouts, turnip, and rutabaga. Beet on the other hand, belongs to the Chenopodiaceae or Amaranthaceae family, which includes spinach and Swiss chard. Kohlrabi is an edible stem, while radish and beet are edible root vegetables. What are the other physical, nutrition, and cultivation differences (and similarities) between these three nutrient-rich vegetables?
Physical Differences between Kohlrabi, Radish, and Beet
Kohlrabi’s botanical name is Brassica oleracea. It resembles something that could’ve landed in Roswell, New Mexico in the late 1940s with its randomly-placed, upright leaf stalks, extending from the bulbous stem near the plant’s base. Besides the already-mentioned purple variety, there is pale green (more commonly seen) and white. Kohlrabi’s creamy white flesh has a crunchy, juicy texture and sweetish favor.
Radish’s botanical name is Raphanus sativus. The small, round root vegetable with its little rat-tail root extension has white, the more common crimson red, and black varieties in addition to the purple. You’ll see names like Burpee White, White Icicle, French Breakfast, Cherry Belle, Rat Tail, and the Japanese Daikon. Its texture is crisp and juicy. Its flavor is somewhat pungent or sweet, depending on variety.
Beet’s botanical name is Beta vulgaris. The common physical features of the round root vegetable are its medium-size and reddish-purple color. Other varieties are white, orange-yellow, and stripped. Like kohlrabi and radish, beet has a crisp, juicy texture and rather sweet flavor. The sweetness is due to its high sugar content, which makes it a sugar-producing crop.
Nutrition Differences (and Similarities) between Kohlrabi, Radish, and Beet.
Kohlrabi offers great sustenance, including antioxidant and anti-inflammatory nutrients, vitamins, and minerals. It also has a reservoir of fiber and some protein. Studies show the phytochemicals, which performs the antioxidant and anti-inflammatory functions, help prevent cancers, diabetes, Alzheimer’s disease, heart or coronary disease, and osteoporosis. The journal Acta Horticulturae (International Society for Horticultural Science) published a 2010 Dutch study on purple kohlrabi, which found that the glucosinolates had the ability to prevent cancer from spreading and may completely expunge it from the body.
Kohlrabi’s B-vitamins, which include thiamine/ B-1, riboflavin/ B-2, niacin/ B-3, pantothenic acid/ B-5, pyridoxine/ B-6, and folate/B-9 help us maintain healthy skin, nails, and hair, while boosting our metabolism. Vitamin B-9 also aids in our cells’ DNA synthesis. Its rich vitamin C content acts an antioxidant, improves our immune system, increases our metabolism, and helps us maintain good bone, skin, and oral health.
Kohlrabi also has an abundance of important minerals: potassium, which helps to convert our body’s glucose into energy and aids in protein-synthesis; manganese, which acts as an antioxidant; copper, which helps us absorb iron; and traces of iron, calcium, magnesium, and selenium. Its fiber supply helps in digestion and weight loss.
Radish also has significant quantities of antioxidant and anti-inflammatory compounds, vitamins, minerals, and fiber. Research conducted by the Jawaharlal Nehru Technological University in India and published in the September 2010 issue of Plant Foods for Human Nutrition showed that consumption of radish aided in the eradication of cancer cells. This vegetable proves particularly strong in fighting against oral, stomach, intestinal, colon, and kidney cancers. Radish’s anthocyanins also prevent other diseases and ailments such as cardiovascular, diabetes, jaundice, urinary, and fevers.
Its B-complex vitamins: B-2, B-6, and B-9 in particular, along with vitamin C help maintain healthy skin, nails, hair, and enhance our immune system, which in turn prevents infections such as asthma, bronchitis, and sinusitis. Vitamin B-9 also helps to synthesize our DNA, and the vitamin C acts as an antioxidant.
The minerals, which include potassium, copper, zinc, phosphorus, manganese, calcium, and iron help to reduce blood pressure and increase blood flow. Potassium is especially helpful with the latter. Zinc and phosphorus treat skin issues. Fiber and the high-water content combine to promote digestive health and weight loss. Overall, radish root is a superb detoxifier and diuretic. This makes for healthy functioning liver, kidneys, and bladder.
The main antioxidant and anti-inflammatory compounds in beets are called betalains. They’re also responsible for the root vegetable’s vibrant colors. Betacyanins produce the red-purple hues and betaxanthins produce the yellows. They help prevent and reduce the same diseases as kohlrabi and radish: cancers -especially breast, lung, and prostate according to research, type 2 diabetes, atherosclerosis, and other coronary issues. The betalains also help our liver function better by decreasing its fat supply.
Beet’s rich vitamin source include B-3, B-5, B-6, B-9, and C. They help maintain healthy bones, skin, nails, and hair; help synthesize our DNA (vitamin B-9 especially), and help boost our immune system.
The root vegetable’s mineral content include iron, manganese, copper, magnesium, and some potassium – all performing the same functions as they do in kohlrabi and radish. Beet’s dietary fiber content promotes our digestive health and of course, aids in weight loss.
Beets are also rich in nitrates, which our body converts into the nitrous oxide needed for proper blood circulation and blood pressure maintenance. Nitrates have also been proven to give an overall boost to our endurance (See Health.com: What happens to your body when you eat beets).
Cultivation Differences (and Similarities) between Kohlrabi, Radish, and Beet
Kohlrabi is a biennial vegetable. It can be cultivated in spring and fall, favoring cooler weather. Spring seedlings can start indoors at a suggested four to six weeks before your last frost. Fall seeds can be planted about six weeks before your first frost. Once outdoors, plants require soil to be moist, nitrogen-rich, fertile, and well-drained with a balanced ph. Esteemed gardeners recommend feeding the plants a healthy dose of fish emulsion every other week, and covering soil with mulch or grass clippings to prevent it from drying out. Plant seeds or seedlings about a quarter-inch deep, and at least eight inches apart in rows. Seed to maturity takes roughly 30-something to 65 days, depending on kohlrabi variety.
Harvest by pulling up plants when vegetable bulbs are about two to three inches in diameter. Larger ones will produce poor texture and taste. Kohlrabi bulbs will keep for several weeks in the refrigerator. Make sure the bag is perforated, if one is used.
Radish like Kohlrabi is a biennial vegetable. Spring plant date is four to six weeks before your last frost. Fall planting is four weeks before your first frost. Soil requirements are similar to Kohlrabi’s. But the vegetable enjoys full sun. Sow seeds or plantings half- to one-inch deep in the soil and about twelve inches apart in rows. Seed to maturity is fast. Vegetables can be reaped three weeks after planting, depending on variety.
Harvest by pulling or gently digging up plants when leaves are about four inches long. Root bulbs should be about one and a half to two inches in diameter for great texture and flavor. Store in the fridge in individual plastic bags for up to three weeks.
Beets are also biennial and are as fast-growing as radishes. Full sun or a bit of shade is fine. Experts say soil should be organically-fertile, moist, and well-drained. So, weed and mulch appropriately. Experts also recommend sowing directly from the seeds, but they may first require de-clumping and an overnight soak to soften the hard skin. Plant them half- to one-inch deep into soil and about two to three inches apart in rows. For spring planting, soil should be at least 50 degrees Fahrenheit (10 Celsius). Fall seeds should be sowed one month before your first frost. Seed to maturity takes about 50 days or less, depending on variety.
Harvest by pulling or gently digging up before leaves reach five to six inches tall. Beet root diameter should be one and a half to two inches. If left longer, they will keep growing and will be too fibrous. Beets can be refrigerated for several weeks.
Cooking Kohlrabi, Radish, and Beet
Trim tops and bottoms of the vegetable, wash and peel or peel and wash then slice, dice or chunk, season, and roast, steam, stir fry, grill, put in soup, use with dips, or grate raw in cole slaw and salads.
Remove radish leaves, if attached, wash bulbs thoroughly, no need to peel. Slice, dice, or use whole depending on whether you are using the vegetable raw in salads, in sandwiches, steaming, roasting, adding to soup, or pickling.
Remove beet leaves, if attached, wash bulb thoroughly and prep without peeling (unless skin is tough). Slice, chunk, dice, or use whole. Grate raw beets in salads, or steam, roast, grill, pickle, add to soups (borscht), curries, use as a side dish, or drink as juice. Because of its high sugar content, you can also make jams, jellies, ice-cream, or sauces.
When selecting kohlrabi, radish, and beet from the store look for fresh, firm, unblemished vegetables, with leaves attached. The leaves of all three vegetables are edible and also provide excellent nutrients.
How Safe Is Kohlrabi, Radish, and Beet to Eat?
Kohlrabi like other cruciferous vegetables contain compounds called goitrogens, which could cause swelling of the thyroid gland. So, people with thyroid disorders may want to avoid it. Kohlrabi also has uric and oxalic acids, which may be problematic for sufferers of gout and kidney diseases. Some people may be allergic as well.
Radish should be avoided by people suffering from kidney stones, ulcers, and women who are pregnant or breast feeding. Consuming large quantities could irritate the digestive tract. Radish may also interact poorly with ginseng.
Beet has a very high oxalate content, so consumption should be avoided by people with gout and kidney diseases. It can also make your urine red/ pink and your stool dark. This is a non-harmful condition is called Beeturia.
If uncertain about consumption of kohlrabi, radish or beet, consult your health professional. This article is merely providing information.
Brief History of Kohlrabi, Radish, and Beet
Believed to be indigenous to Northern Europe, kohlrabi was cultivated in Germany in the 1500s where it remains a popular choice of vegetables today. By the end of the 16th century, it had also gained prominence in Northern French, Hungarian, Italian, Russian, and Asian cuisine. When immigrants from these countries came to the Americas at the beginning of the 19th century, kohlrabi came with them.
Radish is said to have originated in China and made its way to Europe in the 1500s. It is family to horseradish, which is found in the popular Japanese condiment wasabi. Radish was imported to the United States - Massachusetts in 1629, but currently grows mainly in Florida and California.
A wild version of the tuberous root is believed to be native to North Africa, but it has also been found growing wild along the sea coasts of Europe and Asia. Ancient Romans were the first to eat the root. Everyone else consumed the leaves. Beets became a valuable sugar source in the 19th century. That was also when they were first brought to the United States. The United States is now a leading producer of beets along with Russia, Germany, France, and Poland.
Beverley Byer (author) from United States of America on February 17, 2017:
Great! Thanks for commenting, Terrielynn1!
Terrie Lynn from Canada on February 17, 2017:
Great information. Thank you. I like them all, but kohlrabi has more memories.
Beverley Byer (author) from United States of America on December 14, 2016:
Pamela Oglesby from Sunny Florida on December 13, 2016:
Very informative article. I love beets and radishes. I appreciate all your great information about growing these vegetables.